/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package flex.messaging.util;

/**
 * Simple assert class which provides functionality similar to the assert API
 * of JDK 1.4.
 *
 * Enable as follows:
 * java -Dassert
 * 
 * @exclude
 */
public class Assert 
{
    public static final boolean enableAssert = (System.getProperty("assert") != null);

    
    /**
     * If assertions are enabled and the passed in expression is false, throw an
     * AssertionFailedError.
     * 
     * @param expr expression whose truth value is tested
     */
    public static void testAssertion(boolean expr) 
    {
        if (enableAssert && !expr) 
        {
            throw new AssertionFailedError();
        }
    }
    
    /**
     * If assertions are enabled and the passed in expression is false, throw an
     * AssertionFailedError with the passed in message.
     * 
     * @param expr expression whose truth value is tested
     * @param message message contained in the AssertionFailedError when the expression
     * is false and assertions are enabled. 
     */
    public static void testAssertion(boolean expr, String message)
    {
        if (enableAssert && !expr) 
        {
            throw new AssertionFailedError(message);
        }
    }

}

